Research team finds way to use photon shape to encode messages

(Phys.org) -- In their quest to find the perfect encryption technique, scientists have often looked to light, or more specifically, photons. Current techniques allow for sending signals as 1’s or 0’s based on the polarization of individual photons, i.e. they are either vertical or horizontal. But now it appears there is a better way, using the unique shape of photons to represent as many characters as needed, the alphabet, for example. A team of international researchers has, as they describe in their paper published in the journal Physical Review Letters, found a way to use lasers to identify unique shapes of photons and to then recover information that was encoded in them.

The problem with using the shape of a photon for encryption, at least up till now, has been that its shape is based on predicting it at a given time and place, and the fact that its shape will be distorted when it’s sent through media, such as a fiber optic cable. To get around these problems, the team, led by Marco Bellini fired a laser beam in the same direction as a moving photon, which either canceled out the photon’s signal or increased its strength, thus making it easier to detect. To find just the right laser shot, the team fired multiple short bursts until landing on the one that strengthened the signal enough to be measured.

To reduce the number of test shots that needed to be fired to optimize the photons signal strength (i.e. instead of firing random laser pulses until hitting on just the right one) the team very ingeniously used a genetic algorithm to fine tune the parameters, and because of that, were able to zero in on just the right one far more quickly.

Then, having devised a means for detecting the signal from the photon, the team proved their technique allowed for the decoding of data within it, by emitting photons that were specifically shaped according to preset frequencies and then detecting those frequencies using their laser technique. As further proof they then set the frequency of a photon to its opposite phase, which of course was not detected by the laser, thus proving that they were detecting only the photon signal they were actually looking for.

The technique the team developed won’t result in break-proof encryption technology any time soon of course, but it does show that it’s truly possible, which should be more than enough to inspire further research.

(Phys.org) -- When two photons simultaneously enter two input ports of a beam splitter, their paths interfere destructively, which causes the photons to simultaneously exit the beam splitter through the same output port. ...

(PhysOrg.com) -- In a recent article in Applied Physics Letters, CNST researchers demonstrated how commercially available electro-optic modulators can be used to tailor the single photon output of quantum dots (QDs) for us ...

Managing light to carry computer data, such as text, audio and video, is possible today with laser light beams that are guided along a fibre-optic cable. These waves consist of countless billions of photons, ...

Recommended for you

Dielectric elastomers are novel materials for making actuators or motors with soft and lightweight properties that can undergo large active deformations with high-energy conversion efficiencies. This has ...

Plants living in arid, mountainous and humid regions of the planet often rely on their leaves to obtain the moisture they need for survival by pulling mist out of the air. But how exactly they manage this ...

There are electrical signals in the nervous system, the brain and throughout the human body and there are tiny magnetic fields associated with these signals that could be important for medical science. Researchers ...

(Phys.org)—A pair of Turkish space scientists with Bogazici University has proposed that researchers looking for the existence of Dyson spheres might be looking at the wrong objects. İbrahim Semiz and ...

So secretive were efforts to create the first self-sustained nuclear reaction in 1942 that physicist Enrico Fermi and his Manhattan Project team quietly toiled beneath the stands of Stagg Field and communicated ...

In their quest to find the perfect encryption technique, scientists have often looked to light, or more specifically, photons. Current techniques allow for sending signals as 1s or 0s based on the polarization of individual photons, i.e. they are either vertical or horizontal.

By the way, it is interesting to note that nowadays physicists still could not explain what the photon is and how it was created. Indeed it is the same situation that Richard P. Feynman (Nobel Prize winner) could not answer his father while they are still alive! May be this unconventional physical view could help us to understand the mechanism. http://www.vacuum...id=21=en